Journal of thermal analysis

, Volume 46, Issue 2, pp 337–345 | Cite as

High pressure studies on new chiral compounds exhibiting TGBA phase

  • A. Daoudi
  • A. Anakkar
  • J. -M. Buisine
  • F. Bougrioua
  • N. Isaert
  • H. T. Nguyen
13th IUPAC Conference on Chemical Thermodynamics

Abstract

Effects of high pressures on phase sequences of the two homologousn=16 andn=18 of the (3-fluoro-4 ((R) or (S)-methylheptyloxy) 4, (4″-fluoro benzoyloxy) tolans) series have been studied. Both compounds exhibit the new twisted Smectic A phase called Twist Grain Boundary TGBA phase. The high pressure experiments were performed by thermobarometric analysis. The order of the transitions (first or second) have been determined in respect to pressure and temperature. The pressure-temperature phase diagrams show that the TGBA phase is stabilized by increasing pressure; an inducedN* phase appears under high pressure for n=18 leading to the observation of TGBA-N*-I triple point.

Keywords

thermobarometric analysis Twist Grain Boundary phase 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    S. R. Renn and T. C. Lubensky, Phys. Rev. A, 38 (1988) 2132.PubMedGoogle Scholar
  2. 2.
    S. R. Renn, Phys. Rev. A, 45 (1992) 953.PubMedGoogle Scholar
  3. 3.
    J. W. Goodby, M. A. Waugh, S. M. Stein, E. Chin, R. Pindak and J. S. Patel, Nature, 337 (1989) 449.Google Scholar
  4. 4.
    A. Bouchta, H. T. Nguyen, M. F. Achard, F. Hardouin, C. Destrade, R. J. Twieg, A. Maaroufi and N. Isaert, Liq. Cryst., 12 (1992) 575.Google Scholar
  5. 5.
    H. T. Nguyen, A. Bouchta, L. Navailles, P. Barois, N. Isaert, R. J. Twieg, A. Maaroufi and C. Destrade, J. de Phys. II France, 2 (1992) 1889.Google Scholar
  6. 6.
    J. W. Goodby, M. A. Waugh, S. M. Stein, E. Chin, R. Pindak and J. S. Patel, J. Am. Chem. Soc., 111 (1989) 8119.Google Scholar
  7. 7.
    H. T. Nguyen, R. J. Twieg, M. F. Nabor, N. Isaert and C. Destrade, Ferroelectrics, 121 (1991) 187.Google Scholar
  8. 8.
    A. J. Slaney and J. W. Goodby, Liq. Cryst., 9 (1991) 849.Google Scholar
  9. 9.
    O. D. Lavrentovich, Yu. A. Nastishin, V. I. Kulishov, Yu. S. Narkevitch, A. S. Tolochko and S. Shiyanovskii, Europhys. Lett., 13 (1990) 313.Google Scholar
  10. 10.
    A. Anakkar, A. Daoudi, J.-M. Buisine, N. Isaert, T. Delattre, H. T. Nguyen, C. Destrade, J. Thermal Anal., 41 (1994) 1001.Google Scholar
  11. 11.
    The TGBc phase is not mentioned in Ref. [4]; it has very recently observed by thermal microscopy forn=12, 13 and 14 homologous by N. Isaert and F. Bougrioua.Google Scholar
  12. 12.
    H. T. Nguyen, J. Chim. Phys., 80 (1983) 83.Google Scholar
  13. 13.
    V. N. Raja, B. R. Ratna, R. Shashidhar, G. Heppke, Ch. Bahr, J. F. Marco, J. O. Indekeu and A. Nihat Berker, Phys. Rev. A, 39 (1989) 4341.PubMedGoogle Scholar
  14. 14.
    J.-M. Buisine and B. Soulestin, Rev. Phys. App., 22 (1987) 1211.Google Scholar
  15. 15.
    J.-M. Buisine, B. Soulestin and J. Billard, Mol. Cryst. Liq. Cryst., 97 (1983) 397.Google Scholar
  16. 16.
    J.-M. Buisine, B. Soulestin and J. Billard, Mol. Cryst. Liq. Cryst., 91 (1983) 115.Google Scholar
  17. 17.
    J.-M. Buisine, Mol. Cryst. Liq. Cryst., 109 (1984) 143.Google Scholar
  18. 18.
    P. Clapeyron, J. Ec. Polytech., 14 (1834) 153.Google Scholar
  19. 19.
    A. N. Kalkura, R. Shashidhar and N. Subramanya Raj URS, J. de Phy., 44 (1983) 51.Google Scholar
  20. 20.
    P. Ehrenfest, Leiden. Comm. Supp., 75B (1933) 8.Google Scholar

Copyright information

© Akadémiai Kiadó 1996

Authors and Affiliations

  • A. Daoudi
    • 1
    • 3
  • A. Anakkar
    • 1
    • 2
  • J. -M. Buisine
    • 1
    • 3
  • F. Bougrioua
    • 1
    • 2
  • N. Isaert
    • 1
    • 2
  • H. T. Nguyen
    • 4
  1. 1.Laboratoire de Dynamique et Structure des Matériaux MoléculairesU.R.A. CNRS n∘801France
  2. 2.Equipe de Physique des Stases AnisotropesUniversité de Lille 1Villeneuve d'Ascq Cédex
  3. 3.Equipe de Thermophysique de la Matière CondenséeUniversité du LittoralDunkerque
  4. 4.Centre de Recherche Paul PascalChâteau BrivazacPessacFrance

Personalised recommendations